1. Field of the Invention:
Rotary sliding vane compressors with magnetic means to effect vane retraction when pumping capacity is not wanted. This subject matter is believed to be classified principally in Class 418, Subclass 158.
2. Description of the Prior Art:
Stenger (U.S. Pat. No. 2,249,059) is representative of a number of references showing a rotary sliding vane pump or compressor wherein the vanes are urged outwardly by means of a permanent magnet arrangement. Variations of this same type of apparatus are also found in U.S. Pat. Nos. 2,670,895, 2,952,249 and 2,250,947.
U.S. Pat. No. 2,696,790 shows a mechanical arrangement for moving the vanes radially between fully extended and fully retracted positions so that capacity may be varied. Other mechanical devices for the same purpose may be found in U.S. Pat. Nos. 2,880,677, 2,175,413, 2,535,267 and 1,603,437.